.avi failed to decompress????

Last night didn't turn out quite like I was hoping. For one, I didn't notice that the laptop was running low on drive space, and I think that was giving my 1280 resolution a choppy real-time image on my screen (although as it turns out it was okay processed). However, I've run into this problem a few times: when the file gets large enough (over 1 gig) I get a ".avi failed to decompress" message in Registax. Can it not handle files that large?

This question raises another for me concerning framerate. Tutorials all over the net say that 5-10 fps is the recommendation, but isn't that for USB 1 lines? My laptop is fairly new, and both the camera and it have USB 2 standards. I put my fps at 20 most times, but have even gone up to 23 and as low as 5 fps, but I can't see a difference (for individual frames). The only reason I try and push the fps is b/c of lack of guiding. About half of my .avi files last night have failed to process b/c of this error.

I think this is the best from last night from the .avi's I was able to save. You can see a difference between the shadow and Callisto, but I don't know if I'm over analyzing by seeing the left limb having detail. I can't wait to see what you guys did with this image tonight!



Here is the same image, same time, in Celestia.

Guy,

The reason most recommend using low framerates of 5-10 fps is that the framerate should not exceed the exposure time. For example, if you're shooting at an exposure time of 0.2 seconds, then regardless of the transfer speed, you can only get 5 real frames per second. If you set the frame rate to 20 fps for this exposure time, you'll get frame duplication.

If you have the light for it, sure you can adjust your exposure time to a faster value and capture at faster frame rates, but when you're dealing with planetary targets typically most people shoot at really long f-ratios (I shoot at anywhere from f/30 to f/48), and this limits the available light.

Also, I too have had the dreaded ".avi failed to decompress" message in Registax for videos exceeding 1 gig in size. Download Virtualdub, and use it to split your large video into multiple files, each less than 1 gig segments. Process each of these individually and then you can stack the resulting frames from each segment into a single image again in Registax. This has worked for me in the past.

Anjal.